Term
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Definition
| undifferentiated cells; can divide to replace themselves or become osteoblasts |
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Term
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Definition
| form matrix and fibers, but cannot divide |
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Term
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Definition
| mature cells that were osteoblasts, but have enclosed themselves in matrix and can not longer secrete matrix. |
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Term
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Definition
| huge cells from fused monocytes (WBCs); function in bone reabsorption at surfaces like the endosteum |
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Term
| fracture hematoma formation |
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Definition
first step in healing of fractures; damaged blood vessels produce a clot in 6-8 hours, bone cells die;
inflammation brings in phagocytic cells for clean-up duty;new capillaries grow into damaged area |
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Term
| fibrocartilagenous callus formation |
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Definition
| second step in healing of fractures; fibroblasts invade and lay down collagen fibers; chondroblasts produce fibrocatilage to span the broken ends of the bone. |
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Term
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Definition
| third step in healing of fractures; osteoblasts secrete woven bone that joints 2 broken ends of the bone; lasts 3-4 monts. |
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Term
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Definition
| fourth and last step in healing of fractures compact bone replaces tech spongy in the bony callus; surface is remodeled back to normals shape |
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Term
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Definition
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Term
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Definition
Gavriil Ilizarov;
a) deformed bone is cut
b) fixator is attached and slowly pulls and/or rotates the cut ends of the bone
c) osteoblasts lay down new matrix, and bone is remodeled |
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Term
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Definition
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Term
| Why is healing faster in bone than in cartilage? |
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Definition
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Term
| Even though healing of bone is faster than healing of cartilage, why is healing of bone still a slow process? |
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Definition
| Because of vessel damage. |
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Term
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Definition
| clinical treatment for a fracture; restoring pieces to original position by external manipulation |
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Term
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Definition
| clinical treatment for a fracture; surgery |
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Term
| bone remodeling (in general): |
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Definition
| osteoclasts carve out small tunnels and osteoblasts rebuild osteons |
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Term
| bone remodeling (specific steps): |
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Definition
-osteoclasts form leak-proof seals around edge of cell, secrete enzymes and acids beneath themselves, and release calcium and phosphorus into interstitial fluid.
-then osteoblasts take over bone remodeling |
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Term
| There is continual redistribution of bone matrix where? |
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Definition
| Along lines of mechanical stress. |
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Term
| What is an example of continual redistribution of bone matrix along lines of mechanical stress? |
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Definition
| The distal femur is fully remodeled every 4 months. |
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Term
| What hormone prevents bone loss? |
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Definition
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Term
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Definition
| pull on bone by skeletal muscle and gravity |
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Term
| What does mechanical stress increase? |
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Definition
| Mechanical stress increases deposition of mineral salts and production of collagen. |
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Term
| What does lack of mechanical stress result in? |
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Definition
| Lack of mechanical stress results in bone loss. |
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Term
| How does bone length growth happen? |
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Definition
| Cartilage cells are produced by mitosis on the epiphyseal side of the growth plate; then they are destroyed and replaced by bone on the diaphyseal side of the plate. |
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Term
| When do growth plates close? |
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Definition
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Term
| When does bone length growth stop? |
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Definition
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Term
| How do epiphyseal growth plates close? |
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Definition
| Cartilage cells stop dividing and bone replaces cartilage; epiphyseal line created. |
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Term
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Definition
| marks the fusion of diaphysis and epiphysis |
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Term
| Name the zones of growth in the epiphyseal plate. |
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Definition
Resting, Proliferating, Hypertrophic, Calcified.
Recess Produces Hyper C(k)ids. |
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Term
| Zone of resting cartilage |
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Definition
| 1st layer: anchors growth plate to bone |
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Term
| Zone of proliferating cartilage |
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Definition
| 2nd layer: rapid cell division (stacked coins) |
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Term
| Zone of Hypertrophic cartilage |
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Definition
| cells are enlarged, remain in columns |
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Term
| Zone of calcified cartilage |
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Definition
-thin zone
-mostly dead cells, since the matrix is calcified
-osteoclasts remove matrix
-osteoblasts and capillaries move in to create bone over calcified cartilage |
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Term
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Definition
| bone growth by width; at bone's surface |
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Term
| How does appositional growth happen? |
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Definition
| Periosteal cells differentiate into ostoblasts and form bony ridges, then tunnel around periosteal blood vessels; then concentric lamellae fill int the tunnel to form an osteon. |
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Term
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Definition
| in appositional growth: differentiate into osteoblasts and form bony ridges, then tunnel around periosteal blood vessels. |
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Term
| How do concentric lamellae play a role in appositional growth? |
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Definition
| Concentric lamellae fill in the tunnels created by periosteal/osteoblasts around periosteal blood vessels to form an osteon. |
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Term
| Factors affecting bone growth (2)? |
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Definition
Nutrition - adequate levels of minerals and vitamins
Hormones - sufficient levels of specific hormones. |
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Term
Factors of bone growth: Nutrition.
What's needed? |
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Definition
Calcium and phosphorus - growth
Vit C - collagen formation
Vit K and Vit B12 - protein synthesis |
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
| Hormones for growth needed? |
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Definition
hGH - growth
thyroid (T3 and T4)
insulin |
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Term
| What hormones are present at puberty related to growth? |
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Definition
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Term
| At puberty, sex steroids result in... |
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Definition
| growth spurt and closure of epiphyseal plate. |
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Term
| During puberty, what specific bone growth takes place in females and what hormone causes it? |
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Definition
| Estrogen promotes female changes like a wider pelvis. |
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Term
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Definition
| produced by oversecretion of hGH during childhood |
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Term
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Definition
| produced by the undersecretion of gHG or thyroid hormone during childhood |
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Term
| men and women growing taller than normal? |
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Definition
| They lack estrogen receptors on cells. |
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Term
| Why does the lack of estrogen receptors on cells relate to people growing taller than normal? |
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Definition
| Estrogen is responsible for the closure of growth plates. |
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Term
| Skeleton = resevoir of... |
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Definition
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Term
| What are some body processes that calcium ions are involved in (3)? |
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Definition
-nerve and muscle cell function
-blood clotting
-enzyme function in many biochemical reactions |
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Term
| Plasma level usually maintained |
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Definition
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Term
| Small changes in blood levels of _____ can be deadly. |
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Definition
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Term
| If the plasma levels of Ca+2 are too high, this results in... |
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Definition
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Term
| If the plasma levels of Ca+2 are too low, this results in... |
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Definition
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